Individual protector.



F. B. OOOK.

INDIVIDUAL PROTECTOR. APPLIOATION FILED JUNE 10,1908.

9 1 9,696, Patented Apr. 27, 1909.

2 SHEETS-SHEET l.

I. B. 000K.

INDIVIDUAL PROTECTOR. APPLIUATION FILED JUNE710,1908. 919, 9 Patented A.27, 1909.

2 SHE -SHEET 2.

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FRANK B. COOK, OF CHICAGO, ILLINOIS.

INDIVIDUAL PROTECTOR.

Specification of Letters Patent.

Patented April 27', 1909.

Application filed June 10, 1908. Serial No. 437,722.

To all whom it may concern:

Be it known that I, FRANK B. (.ooK, a citizen of the United States ofAmerica, residing at Chicago, in the county of Cook and State ofIllinois, have invented a new and useful individual Protector, of whichthe following is a specification, reference being had to theaccompanying drawings, illustrating same.

My invention relates to electrical protective devices and more inparticular to protective devices of the individual type, such as arecommonly used at telephone substations.

The principal objects of my invention are to provide an improvedmounting base or block for an individual protector; to provide improvedmeans for inclosing the fuses in such a protector; to provide animproved fuse for various kinds of protective devices; to provide animproved lightning arrester for protectors of the character specified toprovide an improved arrangement of the fuses and lightning arresters insuch a protector; and to provide accessibility and simplicity ofconstruction in such a device.

ther objects will be apparent from the following specification.

in the accompanying drawings Figure 1 is a side elevation of thepreferred form of individual protector of the present invention; Fig. 2is a right-hand end view of Fig. 1 Fig. I; is a plan view of Fig. 1,with portions shown in cross-section taken on plane a: :0 of Figs. 1 and2; Fig. 4 is a longitudinal crosssectional view of one of the bindingposts or metallic connection terminals carried by the base portion ofthe protector, showing the method of attaching the fuse wire to theterminal; Fig. 5 is a cross-sectional View of the clamping washer usedon the connection terminal shown in Fig. 4; Fig. 6 is a side elevationof the preferred form of fuse wire used in this present invention,showing the wire crimped for purposes hereinafter de scribed; Fig. 7 isan'enlarged longitudinal cross-sectional view of a fuse casing showingthe crimped fuse in place therein; and Fig. 8 is an enlarged transversecross-sectional view of the improved fuse wire of this invention.

Like characters refer to like parts in the several figures.

In the ordinary types of inclosed fuses it is customary to provide atube for each fuse wire, and to employ a pair of such tubes for anindividual protector for a metallic line. In one of applicants patents apair of such tubular fuses are inserted through openings in aporcelainblock, the whole being used as an individual protector. In this presentinvention the ordinary tubes for inclosing the fuse wires are done awaywith and instead of these tubes a heavy block of insulating material,preferably porcelain, is employed for inclosing the fuses, the blockbeing provided with small bores therethrough through which therespective fuse wires are extended and suitably secured to metallicterminal portions mounted on the ends of the block of in sulation.

In the accompanying drawings the numeral 1 represents the block ofinsulating material, and the numeral 2 represents one of, the smallbores through the block 1 for accommodating the fuse wire 3 which isshown in Fig. 6.

'lhe fuseiwire preferably employed in this invention is constructed oftwo metals, an interior core 25 of iron or steel and an exterior sheathor covering 26 of co per surround'mg the iron core, the two meta s beingrolled or drawn down together to the proper size. Such a fuse wireaffords various improvements over other fuse wires generally employed.It may be made to blow on a very small current, say one-quarter of anampere, and at the same time can be readily handled and utilized forfusing purposes. With the ordinary lead or soft fuse wire it is verydifficult to handle or utilize fuses of such small capacity. In thedouble-metal fuse wire of this invention the iron or steel core givesgreat strength to the wire, and the copper sheath thoroughly protectsthe iron or steel core from corrosion and at the same time provides apath of high conductivity. When this fuse wire is blown it gives off amuch smaller quantity of gas than does the ordinary lead or soft fusewire, and is therefore very desirable in inclosed fuses in which it isdesired to reduce the volume of gas as much as possible to prevent thefuse casings from blowing up when the fuses areblown.

The fuse wire 3 of this present invention is preferably crim ed as shownin Fig. 6, so that when it is t n'eaded through a small eylindrical boreas shown in Fig. 7, the most of the wire is held away from the sides ofthe bore. This construction causes the fuse to blow very uniformlybecause the same amount of the surface thereof always touches the sidesof the bore. With the ordinary straight fuse wire some of the wires donot touch the sides of the bore at all, if the wire is stretchedtightly, while others, which are loose, touch the sides of the bore fornearly the entire length of the fuse. This gives a very ununiformity ofoperation in the fuses, due to the ununiform conduction of heat from thefuse wires through the casings.

The insulating base portion 1 is provided with recesses in 1ts ends inwhich the binding posts 4 4 are referably set and cemented, as shown.Eac small bore 2 through the block 1 has a pair of connection terminals4 4 at the o posite ends thereof, each connection termina 4 having alongitudinal bore 5 therethrough in alinement with the bore 2. A fusewire 3 is inserted through each of the bores 5 2 5 and is secured to theouter ends of the terminals 4 4 by small metallic caps 6 6, preferablyas shown in Fig. 4, the fuse wire being bent over the exterior portionof the exterior ends of the terminals 4 4 and the caps 6 6 being thenpressed over the ends of the terminals 4 4 as shown, to clamp the fusewire 3 between the caps 6 6 and the ends of the terminals 4 4. Each ofthe caps 6' 6 is preferably split as shown at 7 so as to properly gripthe end of the terminal 4. This construction provides an arrangementwhereby the block 1 may be readily re-fused, all that is necessary tore-fuse the block being to remove the caps 6 6, insert new fuse wirethrough the bores 5 2 5, and then replace the caps 6 6 on the exteriorends of the terminals 4 4 as shown in Fig. 4. In addition to this thecaps 6 6 also prevent any flame fronr shooting out of the ends of thebores 5 5 when a fuse blows, because they cover up the ends of the bores5 5 and divert the expelled gases back toward the base portion 1 of theprotector. This construction practically forms U-sliaped vents at theouter ends of the respective bores 5 5, whieh vents destroy any flametending to be emitted therefrom and allow only a slight amount of smoketo be emitted from the caps 6 6 toward the base portion 1. I

Orr one end of the block 1 is provided a pair of lightning arresters,each comprising a pair of carbon disks 8 9 and an interposed dielectric,and carried by a terminal post 4, preferably as shown, the line carbon 8makmg electrical connection with the post 4 and the ground carbon 9being insulated from the post 4 and cap 6 by a suitable insulatingbushing, as shown. Each of the lightning arresters is provided with ametallic cupsha ed portion 10 inclosing same preferab as s own, thecup-shaped portions 10 10 being electrically connected with the ends ofa spring member 11 which is suitably mounted on a binding post 12carried by the center portion of one end of the block 1. The cupshapedportions 10 10 hold the ground carbons 9 9 in place and also inclose andprotect the lightning arresters from foreign particles or objects.lightning arresters the nut 13 is loosened and the spring 11 is turnedaround 90 degrees, whereupon the cup-shaped portions 10 1O andthecarbons 8 9, 8 9 may be readily removed from the posts 4 4.

Each of the binding posts 4 carries a pair of nuts 14 14 and a washer15, by which a circuit conductor may be readily secured to the post 4,the circuit conductor being clam ed between the washer 15 and the shouder portion 16 of post 4, and the washer 15 being cut away as at 17 toentrance of the conductor into t e concave portion 18 of the washer 15.This construction of the washer 15 gives a finished appearance to thejoint between the circuit conductor and the binding post 4. The bindingosts 4 4 at the lightning-arrester end of the block 1 are preferablyconnected with the instrument or circuit to be protected, the bindingposts 4 4 at the opposite end of the block 1 being connected with therespective line conductors of a metallic circuit, and the binding post12 being connected with a grounded conductor. The binding post 12 isalso rovided with a'pair of nuts and a washer for clamping the groundedconductor thereto.

The base portion 1 is pro vided with a pair of holes 19 19 for mountingthe protector in place, and is cut away on the underneath side thereofas'at 20, and grooved as at 21, so that any of the circuit conductorsmay be carried underneath the base portion 1 if desired.

It is believed that the operation and the purposes of the fuses andlightning arresters of this invention will be well understood withoutfurther detailed description.

I do not wish to limit this invention to all of the particular detailsof construction herein shown, as various modifications in same may bemade without departing from the scope of the appended claims.

What-I claim as my invention is:

1. A fusible conductor for electrical fuses, having an iron core and acopper sheath surrounding the iron core.

2. A fusible conductor for electrical fuses, com rising a core made of ametal of relative y low conductivity, and a sheath surrounding the coremade of a metal of relatively high conductivity.

3. A fuse of the character described, comprising a casing having acylindrical bore therethrough, and a crimped fuse wire exermit thetending through the said bore whereby a! definite portion of the. fusewire touches the subscribe my name in the presence of two 10 sides ofthe SL1d bore. 1 subscribing witnesses.

4., A fuse of the character described, com- I As inventor of theforegoing I hereunto 5 prising a casing having a, bore therethrough,FRANK COOK" and a crimped fuse Wire extending through? WVitnesses: thebore whereby only a small portion of the FREDERICK R. PARKER,

fuse wire is allowed to touch the casing. i JNO. F. TOMPKINS.

